xgboost/src/metric/elementwise_metric.cu
Jiaming Yuan 1a33b50a0d
Fix compiler warnings. (#7974)
- Remove unused parameters. There are still many warnings that are not yet
addressed. Currently, the warnings in dmlc-core dominate the error log.
- Remove `distributed` parameter from metric.
- Fixes some warnings about signed comparison.
2022-06-06 22:56:25 +08:00

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/*!
* Copyright 2015-2022 by XGBoost Contributors
* \file elementwise_metric.cc
* \brief evaluation metrics for elementwise binary or regression.
* \author Kailong Chen, Tianqi Chen
*
* The expressions like wsum == 0 ? esum : esum / wsum is used to handle empty dataset.
*/
#include <dmlc/registry.h>
#include <rabit/rabit.h>
#include <xgboost/metric.h>
#include <cmath>
#include "../common/common.h"
#include "../common/math.h"
#include "../common/pseudo_huber.h"
#include "../common/threading_utils.h"
#include "metric_common.h"
#if defined(XGBOOST_USE_CUDA)
#include <thrust/execution_policy.h> // thrust::cuda::par
#include <thrust/functional.h> // thrust::plus<>
#include <thrust/transform_reduce.h>
#include <thrust/iterator/counting_iterator.h>
#include "../common/device_helpers.cuh"
#endif // XGBOOST_USE_CUDA
namespace xgboost {
namespace metric {
// tag the this file, used by force static link later.
DMLC_REGISTRY_FILE_TAG(elementwise_metric);
namespace {
/**
* \brief Reduce function for element wise metrics.
*
* The loss function should handle all the computation for each sample, including
* applying the weights. A tuple of {error_i, weight_i} is expected as return.
*/
template <typename Fn>
PackedReduceResult Reduce(GenericParameter const* ctx, MetaInfo const& info, Fn&& loss) {
PackedReduceResult result;
auto labels = info.labels.View(ctx->gpu_id);
if (ctx->IsCPU()) {
auto n_threads = ctx->Threads();
std::vector<double> score_tloc(n_threads, 0.0);
std::vector<double> weight_tloc(n_threads, 0.0);
// We sum over losses over all samples and targets instead of performing this for each
// target since the first one approach more accurate while the second approach is used
// for approximation in distributed setting. For rmse:
// - sqrt(1/w(sum_t0 + sum_t1 + ... + sum_tm)) // multi-target
// - sqrt(avg_t0) + sqrt(avg_t1) + ... sqrt(avg_tm) // distributed
common::ParallelFor(info.labels.Size(), ctx->Threads(), [&](size_t i) {
auto t_idx = omp_get_thread_num();
size_t sample_id;
size_t target_id;
std::tie(sample_id, target_id) = linalg::UnravelIndex(i, labels.Shape());
float v, wt;
std::tie(v, wt) = loss(i, sample_id, target_id);
score_tloc[t_idx] += v;
weight_tloc[t_idx] += wt;
});
double residue_sum = std::accumulate(score_tloc.cbegin(), score_tloc.cend(), 0.0);
double weights_sum = std::accumulate(weight_tloc.cbegin(), weight_tloc.cend(), 0.0);
result = PackedReduceResult{residue_sum, weights_sum};
} else {
#if defined(XGBOOST_USE_CUDA)
dh::XGBCachingDeviceAllocator<char> alloc;
thrust::counting_iterator<size_t> begin(0);
thrust::counting_iterator<size_t> end = begin + labels.Size();
result = thrust::transform_reduce(
thrust::cuda::par(alloc), begin, end,
[=] XGBOOST_DEVICE(size_t i) {
auto idx = linalg::UnravelIndex(i, labels.Shape());
auto sample_id = std::get<0>(idx);
auto target_id = std::get<1>(idx);
auto res = loss(i, sample_id, target_id);
float v{std::get<0>(res)}, wt{std::get<1>(res)};
return PackedReduceResult{v, wt};
},
PackedReduceResult{}, thrust::plus<PackedReduceResult>());
#else
common::AssertGPUSupport();
#endif // defined(XGBOOST_USE_CUDA)
}
return result;
}
} // anonymous namespace
struct EvalRowRMSE {
char const *Name() const {
return "rmse";
}
XGBOOST_DEVICE bst_float EvalRow(bst_float label, bst_float pred) const {
bst_float diff = label - pred;
return diff * diff;
}
static double GetFinal(double esum, double wsum) {
return wsum == 0 ? std::sqrt(esum) : std::sqrt(esum / wsum);
}
};
struct EvalRowRMSLE {
char const* Name() const {
return "rmsle";
}
XGBOOST_DEVICE bst_float EvalRow(bst_float label, bst_float pred) const {
bst_float diff = std::log1p(label) - std::log1p(pred);
return diff * diff;
}
static double GetFinal(double esum, double wsum) {
return wsum == 0 ? std::sqrt(esum) : std::sqrt(esum / wsum);
}
};
struct EvalRowMAE {
const char *Name() const {
return "mae";
}
XGBOOST_DEVICE bst_float EvalRow(bst_float label, bst_float pred) const {
return std::abs(label - pred);
}
static double GetFinal(double esum, double wsum) {
return wsum == 0 ? esum : esum / wsum;
}
};
struct EvalRowMAPE {
const char *Name() const {
return "mape";
}
XGBOOST_DEVICE bst_float EvalRow(bst_float label, bst_float pred) const {
return std::abs((label - pred) / label);
}
static double GetFinal(double esum, double wsum) {
return wsum == 0 ? esum : esum / wsum;
}
};
namespace {
XGBOOST_DEVICE inline float LogLoss(float y, float py) {
auto xlogy = [](float x, float y) {
float eps = 1e-16;
return (x - 0.0f == 0.0f) ? 0.0f : (x * std::log(std::max(y, eps)));
};
const bst_float pneg = 1.0f - py;
return xlogy(-y, py) + xlogy(-(1.0f - y), pneg);
}
} // anonymous namespace
struct EvalRowLogLoss {
const char *Name() const {
return "logloss";
}
XGBOOST_DEVICE bst_float EvalRow(bst_float y, bst_float py) const { return LogLoss(y, py); }
static double GetFinal(double esum, double wsum) {
return wsum == 0 ? esum : esum / wsum;
}
};
class PseudoErrorLoss : public Metric {
PesudoHuberParam param_;
public:
const char* Name() const override { return "mphe"; }
void Configure(Args const& args) override { param_.UpdateAllowUnknown(args); }
void LoadConfig(Json const& in) override { FromJson(in["pseudo_huber_param"], &param_); }
void SaveConfig(Json* p_out) const override {
auto& out = *p_out;
out["name"] = String(this->Name());
out["pseudo_huber_param"] = ToJson(param_);
}
double Eval(const HostDeviceVector<bst_float>& preds, const MetaInfo& info) override {
CHECK_EQ(info.labels.Shape(0), info.num_row_);
auto labels = info.labels.View(tparam_->gpu_id);
preds.SetDevice(tparam_->gpu_id);
auto predts = tparam_->IsCPU() ? preds.ConstHostSpan() : preds.ConstDeviceSpan();
info.weights_.SetDevice(tparam_->gpu_id);
common::OptionalWeights weights(tparam_->IsCPU() ? info.weights_.ConstHostSpan()
: info.weights_.ConstDeviceSpan());
float slope = this->param_.huber_slope;
CHECK_NE(slope, 0.0) << "slope for pseudo huber cannot be 0.";
PackedReduceResult result =
Reduce(tparam_, info, [=] XGBOOST_DEVICE(size_t i, size_t sample_id, size_t target_id) {
float wt = weights[sample_id];
auto a = labels(sample_id, target_id) - predts[i];
auto v = common::Sqr(slope) * (std::sqrt((1 + common::Sqr(a / slope))) - 1) * wt;
return std::make_tuple(v, wt);
});
double dat[2]{result.Residue(), result.Weights()};
if (rabit::IsDistributed()) {
rabit::Allreduce<rabit::op::Sum>(dat, 2);
}
return EvalRowMAPE::GetFinal(dat[0], dat[1]);
}
};
struct EvalError {
explicit EvalError(const char* param) {
if (param != nullptr) {
CHECK_EQ(sscanf(param, "%f", &threshold_), 1)
<< "unable to parse the threshold value for the error metric";
has_param_ = true;
} else {
threshold_ = 0.5f;
has_param_ = false;
}
}
const char *Name() const {
static std::string name;
if (has_param_) {
std::ostringstream os;
os << "error";
if (threshold_ != 0.5f) os << '@' << threshold_;
name = os.str();
return name.c_str();
} else {
return "error";
}
}
XGBOOST_DEVICE bst_float EvalRow(bst_float label, bst_float pred) const {
// assume label is in [0,1]
return pred > threshold_ ? 1.0f - label : label;
}
static double GetFinal(double esum, double wsum) {
return wsum == 0 ? esum : esum / wsum;
}
private:
bst_float threshold_;
bool has_param_;
};
struct EvalPoissonNegLogLik {
const char *Name() const {
return "poisson-nloglik";
}
XGBOOST_DEVICE bst_float EvalRow(bst_float y, bst_float py) const {
const bst_float eps = 1e-16f;
if (py < eps) py = eps;
return common::LogGamma(y + 1.0f) + py - std::log(py) * y;
}
static double GetFinal(double esum, double wsum) {
return wsum == 0 ? esum : esum / wsum;
}
};
/**
* Gamma deviance
*
* Expected input:
* label >= 0
* predt >= 0
*/
struct EvalGammaDeviance {
const char *Name() const { return "gamma-deviance"; }
XGBOOST_DEVICE bst_float EvalRow(bst_float label, bst_float predt) const {
predt += kRtEps;
label += kRtEps;
return std::log(predt / label) + label / predt - 1;
}
static double GetFinal(double esum, double wsum) {
if (wsum <= 0) {
wsum = kRtEps;
}
return 2 * esum / wsum;
}
};
struct EvalGammaNLogLik {
static const char *Name() {
return "gamma-nloglik";
}
XGBOOST_DEVICE bst_float EvalRow(bst_float y, bst_float py) const {
py = std::max(py, 1e-6f);
// hardcoded dispersion.
float constexpr kPsi = 1.0;
bst_float theta = -1. / py;
bst_float a = kPsi;
float b = -std::log(-theta);
// c = 1. / kPsi^2 * std::log(y/kPsi) - std::log(y) - common::LogGamma(1. / kPsi);
// = 1.0f * std::log(y) - std::log(y) - 0 = 0
float c = 0;
// general form for exponential family.
return -((y * theta - b) / a + c);
}
static double GetFinal(double esum, double wsum) {
return wsum == 0 ? esum : esum / wsum;
}
};
struct EvalTweedieNLogLik {
explicit EvalTweedieNLogLik(const char* param) {
CHECK(param != nullptr)
<< "tweedie-nloglik must be in format tweedie-nloglik@rho";
rho_ = atof(param);
CHECK(rho_ < 2 && rho_ >= 1)
<< "tweedie variance power must be in interval [1, 2)";
}
const char *Name() const {
static std::string name;
std::ostringstream os;
os << "tweedie-nloglik@" << rho_;
name = os.str();
return name.c_str();
}
XGBOOST_DEVICE bst_float EvalRow(bst_float y, bst_float p) const {
bst_float a = y * std::exp((1 - rho_) * std::log(p)) / (1 - rho_);
bst_float b = std::exp((2 - rho_) * std::log(p)) / (2 - rho_);
return -a + b;
}
static double GetFinal(double esum, double wsum) {
return wsum == 0 ? esum : esum / wsum;
}
protected:
bst_float rho_;
};
/*!
* \brief base class of element-wise evaluation
* \tparam Derived the name of subclass
*/
template <typename Policy>
struct EvalEWiseBase : public Metric {
EvalEWiseBase() = default;
explicit EvalEWiseBase(char const* policy_param) : policy_{policy_param} {}
double Eval(HostDeviceVector<bst_float> const& preds, const MetaInfo& info) override {
CHECK_EQ(preds.Size(), info.labels.Size())
<< "label and prediction size not match, "
<< "hint: use merror or mlogloss for multi-class classification";
if (info.labels.Size() != 0) {
CHECK_NE(info.labels.Shape(1), 0);
}
auto labels = info.labels.View(tparam_->gpu_id);
info.weights_.SetDevice(tparam_->gpu_id);
common::OptionalWeights weights(tparam_->IsCPU() ? info.weights_.ConstHostSpan()
: info.weights_.ConstDeviceSpan());
preds.SetDevice(tparam_->gpu_id);
auto predts = tparam_->IsCPU() ? preds.ConstHostSpan() : preds.ConstDeviceSpan();
auto d_policy = policy_;
auto result =
Reduce(tparam_, info, [=] XGBOOST_DEVICE(size_t i, size_t sample_id, size_t target_id) {
float wt = weights[sample_id];
float residue = d_policy.EvalRow(labels(sample_id, target_id), predts[i]);
residue *= wt;
return std::make_tuple(residue, wt);
});
double dat[2]{result.Residue(), result.Weights()};
rabit::Allreduce<rabit::op::Sum>(dat, 2);
return Policy::GetFinal(dat[0], dat[1]);
}
const char* Name() const override { return policy_.Name(); }
private:
Policy policy_;
};
XGBOOST_REGISTER_METRIC(RMSE, "rmse")
.describe("Rooted mean square error.")
.set_body([](const char* param) { return new EvalEWiseBase<EvalRowRMSE>(); });
XGBOOST_REGISTER_METRIC(RMSLE, "rmsle")
.describe("Rooted mean square log error.")
.set_body([](const char* param) { return new EvalEWiseBase<EvalRowRMSLE>(); });
XGBOOST_REGISTER_METRIC(MAE, "mae")
.describe("Mean absolute error.")
.set_body([](const char* param) { return new EvalEWiseBase<EvalRowMAE>(); });
XGBOOST_REGISTER_METRIC(MAPE, "mape")
.describe("Mean absolute percentage error.")
.set_body([](const char* param) { return new EvalEWiseBase<EvalRowMAPE>(); });
XGBOOST_REGISTER_METRIC(LogLoss, "logloss")
.describe("Negative loglikelihood for logistic regression.")
.set_body([](const char* param) { return new EvalEWiseBase<EvalRowLogLoss>(); });
XGBOOST_REGISTER_METRIC(PseudoErrorLoss, "mphe")
.describe("Mean Pseudo-huber error.")
.set_body([](const char* param) { return new PseudoErrorLoss{}; });
XGBOOST_REGISTER_METRIC(PossionNegLoglik, "poisson-nloglik")
.describe("Negative loglikelihood for poisson regression.")
.set_body([](const char* param) { return new EvalEWiseBase<EvalPoissonNegLogLik>(); });
XGBOOST_REGISTER_METRIC(GammaDeviance, "gamma-deviance")
.describe("Residual deviance for gamma regression.")
.set_body([](const char* param) { return new EvalEWiseBase<EvalGammaDeviance>(); });
XGBOOST_REGISTER_METRIC(GammaNLogLik, "gamma-nloglik")
.describe("Negative log-likelihood for gamma regression.")
.set_body([](const char* param) { return new EvalEWiseBase<EvalGammaNLogLik>(); });
XGBOOST_REGISTER_METRIC(Error, "error")
.describe("Binary classification error.")
.set_body([](const char* param) { return new EvalEWiseBase<EvalError>(param); });
XGBOOST_REGISTER_METRIC(TweedieNLogLik, "tweedie-nloglik")
.describe("tweedie-nloglik@rho for tweedie regression.")
.set_body([](const char* param) {
return new EvalEWiseBase<EvalTweedieNLogLik>(param);
});
} // namespace metric
} // namespace xgboost